Earthquake is a phenomenon of propagation shaking caused by an interior violent motion of the earth. When a great earthquake breaks out, enormous seismic energy is released, causing massive damage to the earth surface and human engineering, and severely threatening the life and property safety of people. Damage caused by an earthquake to a bridge directly affects smoothness of a lifeline in an earthquake relief process. Therefore, how to enhance an antiseismic capability of a bridge and reduce damage of the bridge caused by an earthquake is a critical problem.
The nature and extent of damage caused to bridge structures vary depending on different structural forms and detail structures of bridges and earthquake motion characteristics on sites of the bridges. A bridge bearing is an important connecting structure between a superstructure and a substructure of a bridge, and its main function is to transfer load of the superstructure to a pier. Although a ratio of a cost of a bearing to a total cost of a bridge structure is very small, the bearing plays a significant role in the bridge structure. The bearing is a relatively weak link in the bridge structure. During an earthquake, if the bearing is damaged, other parts of the bridge are affected greatly, and consequently, earthquake damage becomes worse. Therefore, performance of the bearing decides overall performance of the bridge to some extent.
In a conventional bridge structure, an antiseismic bearing includes a lead rubber bearing, a high damping rubber bearing, an antiseismic pot bearing, a friction pendulum bearing, or the like. Under seismic load, these types of antiseismic bearings still have insufficient antiseismic capabilities, for example, a poor antitorque capability, an insufficient limiting capability, and a low impact resistance capability. In addition, to improve performance and reliability of seismic mitigation and isolation bearings, most bearings need to be used in cooperation with other damper structures. Therefore, a manufacturing process thereof is complex, high performance of materials is required, and a total system cost is greatly increased. From a perspective of environmental protection, pollution of the lead rubber bearing is severe.